Ditto what Carlotta said. Your mother in law sounds like the type of person who deals with hurt and disappointment by sniping. Sadly, I am too but working on it. If she hasn't always been this way, just ignore it and show her by your actions that you are working on your sobriety. Don't let it get to you because that would just feed into it.
My husband and I have been together ten years. Doesn't mean anything. It's been terrible for much of the time. I quit drinking 17 months ago. Husband relapsed. He tells people what a great job he has and how hard he works. What he doesn't tell anyone, because it isn't a good thing, is that he cashes his paycheck every week and gets drunk and high. I see very little if any of it and in fact, have been dipping into savings to make basic bill payments which I shouldn't have to do.
Stay with sobriety. Work a plan. Don't drink. Trusting again? Takes a long time. Focus on you though, not your mother in law. What she thinks is not your business.